This reseach will carry out a discrete data analysis of retirement decisions of older workers using the latest, most sophisticated statistical and econometric procedures available and applying them to data from the Retirement History Survey and/or National Longitudinal Survey. The overall objective of this reseach is to understand better the determinants of older workers' labor market decisions. The research will embody three refinements: recognition of three or more possible outcomes, full interaction between the explanatory variables and health, and attention to mandatory retirement using a wage-until-retirement variable. These refinements will be combined in a single study for the first time. In addition, not one but several discrete data analysis techniques will be used and the results compared. Past research studies have established that many considerations enter into the retirement decision, but the quantitative importance of these factors or their relative magnitudes have not yet been determined. The relative importance of health as versus economic factors such as social security and pensions and the role of occupation and other job characteristics on various demographic groups' decisions to retire are particular areas which HEW's "Research Inventory on Work, Income, and Retirement of the Aged" cites as major research gaps. The proposed research will help fill these gaps by providing more reliable estimates of the effects of the factors leading to retirement.